1. Field of the Invention
The subject invention is generally directed to a broadhead used for hunting game animals and, more particularly, to a broadhead which pivots from a barbed configuration while in flight to a nonbarbed configuration when the broadhead is being withdrawn from a game animal.
2. Description of the Prior Art
A broadhead is a particular type of arrow head which has outwardly extending blades that inflict more extensive damage to a game animal such as a deer. Broadheads have been used in hunting for many years and there are many different broadhead designs which have developed. FIG. 1 shows a side view of a typical example of a prior art broadhead 100 which has cutting blades 102 that extend radially outward from the body 104. The cutting blades 102 are often clipped to the body 104 or affixed by some other means; however, they are sometimes integrally formed with the body 104. The broadhead 100 may have three or four cutting blades 102, and they are spaced at equal angular locations about the body 104 so that the broadhead 100 will be in balance. The body 104 is normally secured to the end of an arrow shaft (not shown) by a threadable connection or the like.
Most states have gaming laws which require that the broadhead 100 be of a certain diameter where the diameter is defined as the width between the radial ends 106 of opposing cutting blades 102. The main objective of any broadhead is to kill its prey as quickly as possible, and wider diameter broadheads 100 will meet this objective more readily since they will inflict more extensive damage as the arrow passes through the animal. Broadheads having less than the legal diameter will tend not to inflict as much damage, resulting in a slower kill that makes recovery of the animal less likely. Animals which are mortally wounded but not recovered are often not reported to the game warden, and this creates problems for proper wildlife management.
In addition, most states have gaming laws which require that the broadhead 100 have a nonbarbed configuration. That is, the angle made by the body 104 and the cutting blade 102 should be less than 90.degree.. As can be seen in FIG. 1, many broadheads 100 meet this criteria by providing a region 108 on the rear portion of the cutting blades 102. Region 108 does not contribute to the cutting impact of the broadhead 100, but merely provides a more acute angle relative to the body 104. The requirement of a nonbarbed configuration relates to the desire of the state gaming commissions that the animal which has been struck by a broadhead should be able to pull the arrow from its body.
The main problem with prior art broadheads 100 experienced by hunters is that wind shear acts on the cutting blades 102 during the flight of the arrow and causes it to drift off course. Hence, prior art broadheads 100 tend to be less accurate than target arrows. The cutting blades 102 also contribute to the overall surface area of the broadhead 100 and, thus, create a frictional drag which slows the arrow during flight. Recently, there has been much effort in addressing the problems of wind shear and wind drag by providing mechanical broadheads with deployable blades. Typical examples of broadheads with deployable blades are found in U.S. Pat. Nos. 4,998,738 to Puckett, 4,976,443 to DeLucia, 4,932,671 to Anderson, Jr., and 2,859,970 to Doonan. These broadheads eliminate or attempt to eliminate the affects of wind shear and drag by causing the cutting blades to remain retracted within a body ferrule during the flight of the arrow. Upon impact with the animal, the blades are intended to spring open to a cutting position which will cause maximum hemorrhaging to the animal. U.S. Pat. Nos. 4,976,443 to DeLucia and 4,932,443 to Anderson, Jr., as well as the co-pending U.S. patent application to Puckett et al. having Ser. No. 07/637,491 filed Jan. 3, 1991, now U.S. Pat. No. 5,082,292, all show mechanical broadheads which have blades that pivot from a barbed "impact" configuration to a nonbarbed "withdrawal" configuration.
A major drawback of the mechanical broadheads described by Puckett, DeLucia, Anderson, and Doonan, is that they are complicated and require the assembly of many parts. The high number of total parts and their mechanical operating mechanism also contributes much to manufacturing costs. Furthermore, a few states in the U.S. do not permit hunting with mechanical broadheads.
FIGS. 1-3 of U.S. Design Patent Des. No. 279,813 to Palizzolo shows a broadhead which has partially retracting pivotable blades which move upward to a nonbarbed configuration to facilitate removal from the animal. A major drawback of Palizzolo's design is that the cutting blades open during flight; not upon impact.